OBD-II code · Powertrain (generic)
P0606 ECM/PCM Processor Fault
The ECU's internal processor self-test has failed. This is a hard module fault — the ECU usually triggers limp-home mode and may not respond to scan tools fully until replaced or repaired.
Is it safe to drive with P0606?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyInternal processor or memory failure
- Less likelyWater ingress / corrosion in module
- Less likelyModule software outdated, reflash may resolve
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Ecm
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.